That last right next to the word “closed” on the figure.
The presentation goes on to propose a solution that looks quite
reminiscent of the end-to-end provisioning of circuit switching,
like in the old copper telephone days.

My favorites, though:

engineers shouldn’t pre-judge answer to these socio-economic issues

NOTE WELL

IETF needs to provide the cost metric

don’t need metric for value — leave that for industry to guess

In other words, engineers, sit down, shut up, and do what you’re told.
Not just engineers, of course.
The telcos know better.
Seems like this was summarized towards the “freedom to degrade competitors”
end of the spectrum:

you’ll get what we infer you want given what you’re doing

OK, I suppose this is just one researcher’s (and the
BT “re-feedback team”)
unofficial remarks at one informal technical session.
But it may also be what a major telco really thinks.